const mongoose = require('mongoose');

const schema = new mongoose.Schema({
  name:{type:String},
  parent:{type:mongoose.Schema.ObjectId,ref:'Category'}
})

schema.virtual('children',{
  localField:'_id',
  foreignField:'parent',
  justOne:false,
  ref:'Category'
})

schema.virtual('newsList',{
  localField:'_id',
  foreignField:'categories',
  justOne:false,
  ref:'Article'
})

module.exports = mongoose.model('Category',schema)